The present invention relates to a method for making three-dimensional structures of nanometric or micrometric dimensions.
In certain technological sectors there are currently used components provided with surface projections having a height of up to 500 micron and arranged according to definite geometries, for example to form channels.
Components characterized by three-dimensional surface structures of the kind indicated are typically used in micro-electro-mechanical systems (MEMS), for the purposes of producing lighting devices, micromechanical devices and microfluidic devices, for example for the production of diffractive optical devices, medical devices, microturbines, etc.
In the state of the art, the aforesaid surfaces with projections of nanometric or micrometric dimensions arranged according to pre-defined patterns are not obtainable by means of processes of machining. To obtain said three-dimensional structures, more or less conventional photolithographic technologies are hence used, according to the height and the type of the projections desired.
The photolithographic processes used for this purpose are extremely complex and costly. Another drawback of the photolithographic processes is that they do not enable three-dimensional structures with high aspect ratio, understood as ratio between the height of a projection and the distance of the latter from an adjacent projection, to be obtained.